If the cardinal rule of holiday dressing is to look festive, who are we to buck tradition? Take inspiration from this shot of Dean Martin—the album cover from the first pressing of Christmas with Dino, featuring 17 yule time favorites recorded between '53 and '66. It reminds us just how cool Martin seemed to make "casual cocktail" look, rocking the relaxed revelry of the season. And since the impersonal corporate gathering has likely been canceled, a seasonal-toned sweater and a pair of slim-cut chinos might be your best bet for an impromptu party at your place. Christmas with Dino, $10, on iTunes